What size wrench for FZR impeller???

Title pretty much says it. I have the shaft holding tool on the way. For the impeller itself though, 26mm is too small, 27mm is too big, and 1 1/16 is also too big (exact same size as 27mm). Did they really make it some odd size so regular tools can't be used? What's the secret?

It's 27mm. I could only find that size box end in 12pt so I use a 1-1/16 6pt. Don't use 12 pt because it's likely to slip & damage the impeller, especially if it's the first time it is being removed. Also, never use an open end wrench because it'll collapse the impeller.

Make sure to use anti-seize when reassembling & make sure to torque it on good, otherwise it'll be a bitch to get it off next time.